Metabolite modulation of Mtb regulators of cell wall biogenesis

项目摘要 尽管有抗生素来对抗结核病，但它仍然是导致死亡的主要原因之一 因为传染病结核分枝杆菌（Mtb）是一种成功的病原体， 在免疫细胞内，有效地建立和维持潜伏的结核病感染。因此了解 建立或维持休眠的机制可以为结核病的新战略提供信息 治疗学 分枝杆菌膜蛋白大（MmpL）蛋白是专门的细胞壁脂质转运蛋白。沿着 这些转运蛋白与其附属的分枝杆菌膜蛋白小（MmpS）蛋白一起， 参与了分枝杆菌的生理学和发病机制。MmpL 3是必需的;而MmpL 4、MmpL 5、MmpL 7、MmpL 8、MmpL 9、MmpL 10、MmpL 11、MmpL 12、MmpL 13、MmpL 14、MmpL 15、MmpL 16、MmpL 17、MmpL 18、MmpL 19、 MmpL 8、MmpL 10和MmpL 11有助于Mtb毒力。相关蛋白MmpL 3和MmpL 11， 我们特别感兴趣的是含有分枝菌酸的脂质的转运。MmpL 3转运海藻糖 它是单霉菌酸盐，并且是分枝杆菌复制和存活所必需的。我们发现MmpL 11转运 单体分枝菌酰二酰基甘油和分枝菌酸酯蜡。这些脂类有时候 被称为“储存脂质”，并与体外休眠细菌相关，并在肉芽肿中积累 结核病患者。因此，似乎MmpL 11在临床相关但知之甚少的， Mtb发病机制方面。 虽然在鉴定MmpL底物方面已经取得了显著进展，但MmpL蛋白的调节仍然是一个未知的问题。 表达及其在不同环境条件下细胞壁重塑中的作用尚未研究。 拟议的研究将表征Mtb转录调节因子的结构和功能， 表达必需的和毒性相关的MmpL和MmpS蛋白。我们的初步数据显示， 脂肪酸直接调节这些独特转录因子的活性。这表明一个模型，其中结核分枝杆菌 可以直接评估和响应脂肪酸中间产物、代谢状态和营养素可用性来控制 mmpL和mmpS基因调控。通过定义MmpL调节的分子机制， 转运蛋白和确定他们的调节子，我们将产生新的见解之间的过渡积极 区分Mtb和潜伏的或非复制的持久性Mtb。 !

PROJECT SUMMARY Despite the availability of antibiotics to combat Tuberculosis (TB), it is one of the leading causes of death due to infectious disease. Mycobacterium tuberculosis (Mtb) is a successful pathogen because it survives within immune cells and effectively establishes and maintains a latent TB infection. Therefore, understanding the mechanisms underlying the establishment or maintenance of dormancy can inform new strategies for TB therapeutics. Mycobacterial membrane protein large (MmpL) proteins are dedicated cell wall lipid transporters. Along with their accessory Mycobacterial membrane protein small (MmpS) proteins, these transporters are crucial players in mycobacterial physiology and pathogenesis. MmpL3 is essential; and MmpL4, MmpL5, MmpL7, MmpL8, MmpL10 and MmpL11 contribute to Mtb virulence. The related proteins MmpL3 and MmpL11 that transport mycolic acid-containing lipids are of particular interest to us. MmpL3 transports trehalose monomycolate and is required for mycobacterial replication and viability. We showed that MmpL11 transports monomeromycolyl diacylglycerol and a mycolate ester wax. These are species of lipids that are sometimes referred to as “storage lipids” and are associated with dormant bacteria in vitro and accumulate in granulomas of TB patients. Therefore, it appears that MmpL11 plays a role in a clinically relevant, but poorly understood, aspect of Mtb pathogenesis. While significant advances have been made identifying MmpL substrates, the regulation of MmpL protein expression and their role in cell wall remodeling in different environmental conditions has not been explored. The proposed studies will characterize the structure and function of Mtb transcriptional regulators that control expression of essential and virulence-associated MmpL and MmpS proteins. Our preliminary data indicate that fatty acids directly modulate activity of these unique transcription factors. This suggests a model where Mtb can directly assess and respond to fatty acid intermediates, metabolic state and nutrient availability to control mmpL and mmpS gene regulation. By defining the molecular mechanisms underlying the regulation of MmpL transporters and identifying their regulons, we will generate novel insights into the transition between actively dividing Mtb and latent or non-replicating persistent Mtb. !